A method for reducing consumption of a crude oil transportation pipeline in an ultra-low pipeline design throughput

Abstract

The present application belongs to the technical field of oil and gas exploitation, and discloses a method for reducing consumption and reforming a crude oil conveying pipeline with ultra-low pipeline design throughput. For a conveying oil pipeline meeting the reforming conditions, a metal pipe with a proper diameter is selected as a vacuum inner pipe according to the inner diameter of the conveying pipeline and the conveying oil volume. The size and model of a centralizer are selected according to the outer diameter of the selected vacuum inner pipe and the inner diameter of the conveying pipeline. The existing crude oil conveying pipeline is pretreated, and a segmented through pipe operation is performed in the vacuum outer pipe, i.e. the vacuum inner pipe is inserted into the vacuum outer pipe, and a vacuum annular space is formed by arranging an annular blind plate. The method solves the problems of low-temperature condensation of the medium in the pipeline caused by heat loss of the pipeline with ultra-low pipeline design throughput and the problems of electric energy and heat energy loss caused by the return conveying measures taken to ensure the operation of the oil conveying pipeline, reduces the pipeline updating cost after the service life of the oil conveying pipeline, and greatly improves the operation effect of the pipeline network.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction technology, specifically to a method for reducing energy consumption in crude oil transportation pipelines with ultra-low pipeline design capacity. Background Technology

[0002] An investigation into the operational pipelines of the Jilin Oilfield's storage and transportation system revealed that pipelines A and B are currently operating at extremely low designed capacity, and have been using reverse transmission for many years. In 2020, pipeline A's total transport volume was 405,100 tons, of which only 138,100 tons were effectively transported, resulting in 267,000 tons of ineffective reverse transmission—approximately twice the effective volume. Pipeline B's total annual transport volume was 293,000 tons, with only 37,000 tons being effectively transported, and 256,000 tons being reverse transmission—approximately seven times the effective volume. Both pipelines exhibit significant energy waste. Pipeline C's designed capacity is approximately three times its operational capacity, and pipeline D's designed capacity is five times its operational capacity. The designed capacity of other pipelines is also more than twice their operational capacity.

[0003] As the output of each plant decreases, the situation where the designed throughput exceeds the operating throughput becomes increasingly serious. The energy loss, especially the heat loss, of each oil pipeline network will become more prominent. Based on the above situation, this technical transformation plan was developed.

[0004] CN111794690A double-layer insulated oil tubing includes a carbon steel layer, an outer tube on the outside of the carbon steel layer, a vacuum layer between the outer tube and the carbon steel layer, and a heat insulation layer and an inner tube on the inside of the carbon steel layer. A support ring is provided between the outer tube and the carbon steel layer, supporting the inner wall of the outer tube. The outer tube is a thin-walled metal tube. This design optimizes the structure of existing oil tubing by incorporating a vacuum layer and a heat insulation layer, effectively reducing the rate of temperature drop of crude oil, thus maintaining a low viscosity of crude oil upon reaching the wellhead and reducing wax deposition on the inner wall of the tubing. However, this design involves remanufacturing a double-layer oil tubing; replacing all existing oil pipelines with this structure would be too costly and difficult to implement. Summary of the Invention

[0005] Based on the above considerations, the present invention aims to solve the problem of reduced throughput caused by declining production, reduced crude oil flow rate in the pipeline, low operating efficiency of the pipeline transportation system due to heat loss, and safety hazards of low temperature condensation.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for reducing energy consumption in crude oil pipelines with ultra-low design throughput includes the following steps:

[0008] Step S1. For oil pipelines that meet the modification conditions, select a metal pipe with a suitable diameter as the vacuum inner pipe based on the inner diameter of the pipeline and the operating oil volume.

[0009] Step S2. Select the centralizer specification and model based on the selected outer diameter of the vacuum inner tube and the inner diameter of the pipeline in operation.

[0010] Step S3. Construction work: The existing crude oil pipeline is pre-treated. In the crude oil pipeline, i.e., the vacuum outer pipe, a segmented core-through pipe operation is carried out, that is, the vacuum inner pipe is inserted into the vacuum outer pipe, and a vacuum annular space is formed by setting an annular blind plate.

[0011] Furthermore, step S3 includes pretreatment of the crude oil pipeline, including: shutting down the transport pipeline, cleaning the residual crude oil and scale from the pipeline walls, and blowing away and drying the residual liquid.

[0012] Furthermore, the construction distance between every two annular blind flanges is 0.5KM-5KM.

[0013] Furthermore, a centralizer is installed between the inner vacuum tube and the outer vacuum tube.

[0014] Furthermore, the segmented through-tube operation involves excavating backfill at fixed intervals along the transport oil pipeline, with the backfill distance from the excavation length meeting the requirement that the vacuum inner tube insertion angle be 165-175 degrees.

[0015] Furthermore, the air in the vacuum annular space is extracted by a vacuum pump, and the vacuum level is controlled between 1 Pa and 100 Pa.

[0016] Furthermore, the outer diameter of the inner vacuum tube is more than 60 mm smaller than the inner diameter of the outer vacuum tube.

[0017] Furthermore, the centralizer design adopts a six-claw design or a four-claw design.

[0018] Furthermore, the centralizer includes rolling elements and a support, which are movably connected.

[0019] Furthermore, the claw tip of the rolling element is made of wear-resistant material or a rolling device.

[0020] Compared with the prior art, the present invention has the following features and advantages:

[0021] 1. Solved the problem of low condensation temperature of the medium inside the pipe caused by heat loss in pipelines with ultra-low pipeline design flow rates;

[0022] 2. It solved the problem of power and heat loss caused by the back-transport measures taken to ensure the operation of oil pipelines;

[0023] 3. Reduce the cost of pipeline replacement after the service life of oil pipelines expires; the construction time of this renovation method is also much shorter than that required for pipeline replacement.

[0024] 4. The insulation effect of vacuum tubes is far greater than that of existing pipeline insulation materials, which greatly reduces heat loss and significantly increases the adjustment space for intermittent oil transportation in long-distance oil pipelines, thus greatly improving the pipeline network operation efficiency. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A schematic diagram of the construction section for pipeline energy saving and retrofitting process;

[0027] Figure 2 A schematic diagram of the closed section structure for pipeline energy-saving retrofitting process;

[0028] Figure 3 Front view of the vacuum inner tube centralizer;

[0029] Figure 4 This is a cross-sectional view of the vacuum inner tube centralizer.

[0030] In the diagram, number 1 is an annular blind flange, number 2 is a centralizer, number 3 is a vacuum outer tube, number 4 is a vacuum inner tube, number 5 is a vacuum annular space, number 6 is a vacuum extraction valve, number 7 is a rolling element, number 8 is a support, and number 9 is a claw tip. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] In existing crude oil pipelines, segmented through-tube construction is carried out, and segmented sealing and vacuuming operations are performed in the annular space between the inner and outer tubes, thereby achieving the goal of reducing heat loss by transporting crude oil in double-layer vacuum insulated pipes.

[0034] Existing crude oil pipelines refer to long-distance pipelines in operation whose original designed capacity is much higher than the current capacity. Generally, they are characterized by large pipe diameter, a capacity much lower than the designed capacity, and an early commissioning time. They are referred to as vacuum outer pipes 3 below.

[0035] A through-pipe refers to a pipeline whose diameter meets the existing transport capacity and whose outer wall is equipped with a centralizing device. The outer diameter of the pipe wall is more than 60mm smaller than the inner diameter of the existing crude oil transport pipeline. It is a pipeline that meets the requirements for the installation of the centralizer 2 and the existence of the vacuum annular space 5. It is referred to as the vacuum inner pipe 4 below.

[0036] The centralizer 2 ensures that the inner vacuum tube 4 passes smoothly through the outer vacuum tube 3 and maintains the uniformity and symmetry of the annular vacuum space 5 between the two tube walls. The centralizer 2 can be designed with a six-claw or a four-claw configuration, and the claw tips 9 need to be made of wear-resistant material or have a rolling mechanism to ensure the smooth passage of the inner vacuum tube 4 through the outer vacuum tube 3 and to ensure that the annular vacuum space 5 remains even after wear. The claw-shaped design of the centralizer 2 also ensures that it has channels for gas flow on both sides and minimizes the contact area between the inner vacuum tube 4 and the outer vacuum tube 3, reducing heat loss through conduction.

[0037] Segmented sealing vacuuming refers to the process where, after the inner vacuum tube 4 is installed onto the outer vacuum tube 3, the annular vacuum space 5 is uniform and has been cleaned, purged, and dried. Given that the construction distance is generally between 0.5 and 5 km, the annular space within the segment is sealed before vacuuming. The vacuum level is controlled between 1 Pa and 100 Pa.

[0038] Example 2

[0039] 1. For oil pipelines that meet the modification requirements, select a metal pipe with a suitable diameter as the vacuum inner pipe based on the inner diameter of the pipeline and the operating oil volume.

[0040] 2. Select the specifications and model of the centralizer 2 based on the selected outer diameter of the vacuum inner tube 4 and the inner diameter of the pipeline in operation.

[0041] 3. Construction operations:

[0042] (1) The oil pipeline was shut down;

[0043] (2) Cleaning residual crude oil from the walls of the transport pipeline;

[0044] (3) Cleaning scale and other substances in the oil transport pipeline;

[0045] (4) Purge and dry the residual liquid in the transport pipeline;

[0046] (5) Excavate backfilling at fixed intervals along the transport oil pipeline (the backfilling distance and excavation length must meet the 170-degree insertion angle of the vacuum inner tube 4);

[0047] (6) Disconnect the transport oil pipeline at a certain distance and open the vacuum core tube to enter the channel;

[0048] (7) The vacuum inner tube 4 is pushed into the oil pipeline (vacuum outer tube 3) by power jacking.

[0049] (8) After the jacking pipe reaches the preset distance (where the pipeline is disconnected), the vacuum annular space 5 is sealed with an annular blind flange 1;

[0050] (9) Use vacuum pump 6 to extract air from the vacuum annular space 5, and control the vacuum level between 1pa and 100pa.

[0051] The terms "comprising," "including," or any other variations thereof used in this specification are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. It should be noted that, without conflict, embodiments and features in the embodiments of this invention can be combined with each other. This invention is not limited to any single aspect, nor to any single embodiment, nor to any combination and / or substitution of these aspects and / or embodiments. Moreover, each aspect and / or embodiment of the invention can be used alone or in combination with one or more other aspects and / or embodiments thereof.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for reducing energy consumption in crude oil transportation pipelines with ultra-low design throughput, characterized in that, Includes the following steps: Step S1. For oil pipelines that meet the modification conditions, select a metal pipe with a suitable diameter as the vacuum inner pipe based on the inner diameter of the pipeline and the operating oil volume (4). Step S2. Select the specifications and model of the stabilizer (2) according to the selected outer diameter of the vacuum inner tube (4) and the inner diameter of the pipeline. The stabilizer (2) is installed between the vacuum inner tube (4) and the vacuum outer tube (3). Step S3. Construction operation: The existing crude oil pipeline is pre-treated. In the crude oil pipeline, i.e., the vacuum outer pipe (3), a segmented core-through pipe operation is carried out, i.e., the vacuum inner pipe (4) is inserted into the vacuum outer pipe (3), and a vacuum annular space (5) is formed by setting an annular blind plate (1).

2. The method for reducing energy consumption in crude oil pipelines with ultra-low design throughput as described in claim 1, characterized in that, Step S3 includes pretreatment of the crude oil pipeline, including: shutting down the pipeline, cleaning the residual crude oil and scale from the pipeline walls, and blowing away and drying the residual liquid.

3. The method for reducing energy consumption in crude oil pipelines with ultra-low design throughput as described in claim 1, characterized in that, The construction distance between every two annular blind flanges (1) is 0.5KM-5KM.

4. The method for reducing energy consumption in crude oil pipelines with ultra-low design throughput as described in claim 1, characterized in that, The segmented core pipe operation involves excavating soil at fixed intervals along the transport oil pipeline, with the soil covering distance from the excavation length meeting the requirement that the vacuum inner pipe (4) be inserted at an angle of 165-175 degrees.

5. The method for reducing energy consumption in crude oil pipelines with ultra-low design throughput as described in claim 1, characterized in that, The air in the vacuum annular space (5) is extracted by the vacuum pump (6).

6. The method for reducing energy consumption in crude oil pipelines with ultra-low design throughput as described in claim 1, characterized in that, The vacuum level of the vacuum annular space (5) is controlled between 1 Pa and 100 Pa.

7. The method for reducing energy consumption in crude oil pipelines with ultra-low design throughput as described in claim 1, characterized in that, The outer diameter of the inner vacuum tube (4) is more than 60 mm smaller than the inner diameter of the outer vacuum tube (3) to meet the space requirements for the installation of the centralizer (2).

8. The method for reducing energy consumption in crude oil pipelines with ultra-low design throughput as described in claim 1, characterized in that, The straightener (2) is designed with a six-claw design or a four-claw design.

9. The method for reducing energy consumption in crude oil pipelines with ultra-low design throughput as described in claim 1, characterized in that, The centralizer (2) includes a rolling element (7) and a support (8), which are movably connected.

10. The method for reducing energy consumption in crude oil pipelines with ultra-low design throughput as described in claim 9, characterized in that, The claw tip (9) of the rolling element (7) is made of wear-resistant material or a rolling device.

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